Homolytic and Hetrolytic Fission of a Covalent Bond
- Fission of Covalent Bond
The cleavage of Covalant bond occurs in two ways.
- Heterolytic cleavage and
- Homolytic cleavage
In this type of breaking of the Covalent bond, the shared pair of electrons remains with either of the atoms.
The atom, possessing positive charge has sextet while the other having -ve charge has octet electronic configuration. The carbon atom with positive charge, having sextet configuration is known as Carbocation or Carbonium ion.
The heterolytic cleavage also gives carbon atom with - ve charge and is known as Carbanions.
Carbanions are having octect configuration and has shared pair of electrons.
Carbocations are unstable, but stabilised by inductive effect and conjugation effect. The stability of Tertiary, Secondary and primary Carbocation is in the following order.
(CH3)3 C+ > (CH3)2+CH > CH3 +CH2
The positively charged carbon(C+) is sp2 and carbocations are trigonal in shape.
It gives free radicals. In this type of Cleavage, one electron of shared pair in a covalent bond goes to each of the bonded atoms. The movement is shown by half headed arrow.
The stability of alkyl radicals resembles the stability of Carbocations.